// 文本控件:
    auto laber = new QLabel("I am label!", this);
    laber->move(0,30);
    laber->setFont(QFont("楷体",10,10,0));

    // 滑动条控件
    QSlider* slider = new QSlider;
    slider->setParent(this);
    slider->move(250,30);
    slider->setValue(0);
    slider->setMaximum(100);
    // 通过滑动滑动条改变字体大小
    connect(slider, &QSlider::valueChanged, [laber](int _value){
        laber->setFont(QFont("楷体",_value,10,0));
        laber->resize(400,_value+100);
    });


    // 进度条
    QProgressBar* proBar = new QProgressBar;
    proBar->setParent(this);
    proBar->move(0,200);
    proBar->resize(this->size().width(),20);
    //proBar->setValue(50);
    // 通过滑动条改变进度条
    connect(slider,&QSlider::valueChanged,[proBar](int _value){
       proBar->setValue(_value);
    });